> ## Documentation Index
> Fetch the complete documentation index at: https://extended-openai-conversation.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.
# Template Functions
> Return dynamic values using Jinja2 templates
Template functions use Home Assistant's [Jinja2 templating](https://www.home-assistant.io/docs/configuration/templating/) to return dynamic values. They're ideal for retrieving entity states, attributes, or generating formatted responses.
## Configuration
```yaml theme={null}
function:
type: template
value_template: "{{ your_template_here }}"
```
Jinja2 template that returns the function result
## Examples
### Get Current Weather
This simple example demonstrates template syntax:
```yaml theme={null}
- spec:
name: get_current_weather
description: Get the current weather in a given location
parameters:
type: object
properties:
location:
type: string
description: The city and state, e.g. San Francisco, CA
unit:
type: string
enum:
- celsius
- fahrenheit
required:
- location
function:
type: template
value_template: The temperature in {{ location }} is 25 {{unit}}
```
This is a simplified example from the [OpenAI documentation](https://platform.openai.com/docs/guides/function-calling/common-use-cases).
### Get Entity Attributes
Access state and attributes of one or multiple entities.
````yaml theme={null}
- spec:
name: get_attributes
description: Get attributes of entity or multiple entities.
parameters:
type: object
properties:
entity_id:
type: array
description: entity_id of entity or multiple entities
items:
type: string
required:
- entity_id
function:
type: template
value_template: >-
```csv
entity,attributes
{%for entity in entity_id%}
{{entity}},{{states[entity].attributes}}
{%endfor%}
```
````
This function returns attributes in CSV format, making it easy for the AI to parse and understand multiple entities at once.
## Template Features
```jinja2 theme={null}
{{ states('sensor.temperature') }}
{{ states.sensor.temperature.state }}
{{ state_attr('sensor.temperature', 'unit_of_measurement') }}
```
```jinja2 theme={null}
{% set on_lights = states.light | selectattr('state', 'eq', 'on') | list %}
{{ on_lights | length }} lights are on
```
```jinja2 theme={null}
{{ now() }}
{{ now().strftime('%Y-%m-%d %H:%M:%S') }}
{{ as_timestamp(now()) }}
```
```jinja2 theme={null}
{% set total = (value1 | float) + (value2 | float) %}
{% if total > 100 %}High{% else %}Normal{% endif %}
```
## Use Cases
Retrieve current states and attributes of entities
Perform math operations on sensor values
Format data for natural language responses
Filter entities by state, area, or attributes
## Best Practices
Use template functions for simple data retrieval. For complex logic, consider composite functions.
Always use default values and safe filters:
```jinja2 theme={null}
{{ states('sensor.temperature') | float(0) }}
{{ state_attr('light.bedroom', 'brightness') | default('N/A') }}
```
Return human-readable text that the AI can use in responses:
```jinja2 theme={null}
The temperature is {{ states('sensor.temp') }}°C (feels like {{ state_attr('sensor.temp', 'feels_like') }}°C)
```
## Next Steps
Execute service sequences
Combine templates with other functions
Home Assistant templating guide